The NOS AN Tube Nuts & Sleeves are available in anodized lightweight aluminum construction in a variety of sizes to suit your application and custom hard tube plumbing situation. Blue for Nitrous and Red for fuel options

Note:
Not all nitrous companies use 37° "AN" Fittings in their nitrous kits. To avoid potential leaks, never mix 37° "AN" and 45° SAE fittings.